Method and system for treating desulfurized waste water of flue gas from boiler

Abstract

The invention discloses a method for treating desulfurized waste water of flue gas from a boiler. The method comprises the following steps of: extracting a proper amount of high-temperature flue gas from a flue bypass at the front of an air preheater, feeding the extracted high-temperature flue gas into a drying space, adding flying ash into the drying space, spraying the desulfurized waste waterinto the drying space and mixing the desulfurized waste water with the flying ash to realize evaporation and drying of the desulfurized waste water, forming solid powder after drying, then feeding flue gas mixed with the solid powder into a dust-removing device for treatment, and separating to collect the solid powder in the flue gas. The invention also discloses a system for treating the desulfurized waste water of the flue gas from the boiler. The system comprises a drying container and a dust remover, wherein the drying container is provided with conveying inlets for respectively conveyingthe flying ash and the desulfurized waste water into the drying space; the desulfurized waste water is sprayed into the drying space to be mixed with the flying ash by a spraying nozzle, and the mixture forms solid powder after being dried; an air outlet is communicated with an inlet of the dust remover. The method and system provided by the invention have the advantages that the desulfurized waste water can be dried quickly, the dried solid matters are easily collected, the volume is small, the heat dissipation is less, the equipment manufacturing cost is low and no any wall-scaling phenomenon is caused.

Description

technical field [0001] The invention relates to the technical field of desulfurization wastewater treatment in thermal power plants, in particular to a boiler flue gas desulfurization wastewater treatment method and system. Background technique [0002] In order to reduce sulfur dioxide emissions, my country's coal-fired thermal power plants are equipped with flue gas desulfurization systems, among which limestone-gypsum wet flue gas desulfurization is the most widely used, and the system will generate a certain amount of desulfurization wastewater during operation. The wastewater contains many It is a pollutant that must be treated before discharge. The most widely used treatment method is physical and chemical methods, but this method has complex processes, high operating costs and cannot remove chloride ions. With the advancement of sustainable development, it is necessary to innovate the zero discharge process of desulfurization wastewater and build a more environmentally...

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Problems solved by technology

[0006] (1) The phenomenon of sticking to the wall is serious, and the labor intensity of ash cleaning is high. Sometimes the ash sticking to the wall will suddenly fall off, forming an avalanche phenomenon, which affects the normal operation of subsequent equipment

[0007] (2) The equipment is huge, the heat dissipation loss is large, and the investment is large

[0008] (3) Spray drying has very strict requirements on the nozzle, the structure of the nozzle is complex, and the desulfurization wastewater contains a certain amount of calcium and magnesium ions, the nozzle is easy to block, affecting the normal operation

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